modbusrtuinterface.h

/***************************************************************************
        Copyright (C) 2002-2015 Kentaro Kitagawa
                           kitagawa@phys.s.u-tokyo.ac.jp

        This program is free software; you can redistribute it and/or
        modify it under the terms of the GNU Library General Public
        License as published by the Free Software Foundation; either
        version 2 of the License, or (at your option) any later version.

        You should have received a copy of the GNU Library General
        Public License and a list of authors along with this program;
        see the files COPYING and AUTHORS.
***************************************************************************/
#ifndef MODBUSRTUINTERFACE_H_
#define MODBUSRTUINTERFACE_H_

#include "charinterface.h"
#include "chardevicedriver.h"
#include "serial.h"

class XModbusRTUInterface : public XCharInterface {
public:
    XModbusRTUInterface(const char *name, bool runtime, const shared_ptr<XDriver> &driver);
    virtual ~XModbusRTUInterface();

    void readHoldingResistors(uint16_t res_addr, int count, std::vector<uint16_t> &data);
    void presetSingleResistor(uint16_t res_addr, uint16_t data);
    void presetMultipleResistors(uint16_t res_no, int count, const std::vector<uint16_t> &data);
    void diagnostics();

    uint16_t readHoldingSingleResistor(uint16_t res_addr) {
        std::vector<uint16_t> data(1);
        readHoldingResistors(res_addr, 1, data);
        return data[0];
    }
    uint32_t readHoldingTwoResistors(uint16_t res_addr) {
        std::vector<uint16_t> data(2);
        readHoldingResistors(res_addr, 2, data);
        return data[0] * 0x10000uL + data[1];
    }
    void presetTwoResistors(uint16_t res_addr, uint32_t dword) {
        std::vector<uint16_t> data(2);
        data[0] = dword / 0x10000uL;
        data[1] = dword % 0x10000uL;
        presetMultipleResistors(res_addr, 2, data);
    }
protected:
    virtual void open() throw (XInterfaceError &);
    //! This can be called even if has already closed.
    virtual void close() throw (XInterfaceError &);

    virtual bool isOpened() const {return !!m_openedPort;}

    void query_unicast(unsigned int func_code, const std::vector<unsigned char> &bytes, std::vector<unsigned char> &buf);
private:
    //Modbus utilizes Big endian.
    static void set_word(unsigned char *ptr, uint16_t word) {
        ptr[0] = static_cast<unsigned char>(word / 0x100u);
        ptr[1] = static_cast<unsigned char>(word % 0x100u);
    }
    static void set_dword(unsigned char *ptr, uint32_t dword) {
        set_word(ptr, static_cast<uint16_t>(dword / 0x10000u));
        set_word(ptr + 2, static_cast<uint16_t>(dword % 0x10000u));
    }
    static uint16_t get_word(unsigned char *ptr) {
        return ptr[1] +ptr[0] * 0x100u;
    }
    static uint32_t get_dword(unsigned char *ptr) {
        return get_word(ptr + 2) + get_word(ptr) * 0x10000uL;
    }
    uint16_t crc16(const unsigned char *bytes, uint32_t count);

    struct PortWrapper {
        shared_ptr<XPort> port;
        XTime lastTimeStamp;
        XMutex mutex; //for the port.
    };
    shared_ptr<PortWrapper> m_openedPort;
    static XMutex s_globalMutex;
    static std::deque<weak_ptr<PortWrapper>> s_openedPorts; //should be guarded by s_globalMutex.
};

template <class T>
class XModbusRTUDriver : public XCharDeviceDriver<T, XModbusRTUInterface> {
public:
    XModbusRTUDriver(const char *name, bool runtime,
    Transaction &tr_meas, const shared_ptr<XMeasure> &meas) :
        XCharDeviceDriver<T, XModbusRTUInterface>(name, runtime, ref(tr_meas), meas) {}
    virtual ~XModbusRTUDriver() {};
};

#endif /*MODBUSRTUINTERFACE_H_*/